I didn't bother testing blood because I figured the results would be garbage. I did a dietary trial and that convinced me of everything I needed to know. Then I got tested by a stool test through Enterolab.com. I believe the autoimmune issues I've been wrestling with throughout my life were the result of gluten intolerance, which causes leaky gut. So I've been very, very careful to adhere strictly to the diet, even though I probably don't react strongly to small doses. I think the long term damage to your health can be very significant. I feel like I need to be as fanatical as someone with full blown, diagnosed celiac disease.